4-Chloro-1H-pyrazolo[4,3-c]pyridine: Properties & Uses FAQ

4-Chloro-1H-pyrazolo[4,3-c]pyridine is a bicyclic nitrogen-rich heterocyclic compound widely used as a synthetic building block in medicinal chemistry and drug discovery research.

Chemical Name

4-Chloro-1H-pyrazolo[4,3-c]pyridine

Aladdin SKU

C139367

Core Scaffold

Pyrazolo[4,3-c]pyridine (fused pyrazole–pyridine bicyclic system)

Key Functional Group

C-4 chloro substituent, amenable to nucleophilic aromatic substitution and cross-coupling reactions

Primary Application

Synthetic intermediate for kinase inhibitor and bioactive molecule development

N–H Tautomerism

Exists as 1H-tautomer; the NH group is available for N-alkylation or N-acylation

Overview and Structural Features

4-Chloro-1H-pyrazolo[4,3-c]pyridine (Aladdin SKU: C139367) belongs to the pyrazolopyridine family of fused bicyclic heterocycles. The compound consists of a pyrazole ring fused to a pyridine ring in the [4,3-c] connectivity, with a chlorine atom at the C-4 position and a free N–H at the 1-position (1H-tautomer). This arrangement places three nitrogen atoms within the bicyclic framework, conferring high polarity, hydrogen-bond donor/acceptor capacity, and a planar aromatic character that facilitates π–π stacking interactions relevant to target binding in drug design.

The C-4 chloro group is an electrophilic handle that undergoes nucleophilic aromatic substitution (SNAr) with amines, alcohols, and thiols, as well as transition-metal-catalyzed cross-coupling reactions (e.g., Suzuki, Buchwald–Hartwig), making this scaffold extremely versatile for library synthesis.

Research Applications

The pyrazolo[4,3-c]pyridine scaffold has attracted significant interest in medicinal chemistry as a bioisostere of purines and other fused nitrogen heterocycles. Key research applications of 4-Chloro-1H-pyrazolo[4,3-c]pyridine include:

• Kinase inhibitor development: The scaffold mimics adenine binding motifs, enabling inhibitor design targeting protein kinases involved in oncology, inflammation, and other disease areas.
• Fragment-based drug discovery: The compact, rigid bicyclic structure and balanced physicochemical properties make it suitable as a fragment or fragment-derived hit.
• Diversity-oriented synthesis: Sequential functionalization at the C-4 chloro position and the N-1 nitrogen allows rapid generation of structurally diverse analogue libraries.
• Probe molecule synthesis: Used in the preparation of chemical biology probes for studying kinase biology and signal transduction pathways.

Handling, Storage and Safety

As with most chlorinated heterocyclic compounds, standard laboratory precautions should be observed when working with 4-Chloro-1H-pyrazolo[4,3-c]pyridine:

• Personal protective equipment: Wear appropriate gloves, safety glasses, and a lab coat. Work in a well-ventilated area or fume hood.
• Storage: Store in a tightly sealed container in a cool, dry, well-ventilated location, away from incompatible materials such as strong oxidizers and bases. Specific temperature and stability data should be confirmed from the product's Safety Data Sheet (SDS).
• Handling: Avoid inhalation of dust or aerosols. In case of skin or eye contact, rinse immediately with copious water and seek medical attention as appropriate.
• Disposal: Dispose of in accordance with local, regional, and national regulations for chemical waste.

Always consult the product SDS provided by Aladdin Scientific before use for complete hazard, first-aid, and disposal information.

Ordering and Specifications

4-Chloro-1H-pyrazolo[4,3-c]pyridine is available from Aladdin Scientific under SKU C139367. When placing an order or requesting a quotation, please have the following information ready:

• Product SKU: C139367
• Required quantity and pack size
• Purity grade required for your application
• Destination country and any relevant import/export requirements

For detailed specification sheets, certificates of analysis (CoA), SDS documents, or bulk pricing inquiries, please contact Aladdin Scientific customer service or visit the product page on the Aladdin website. Lead times and availability are subject to stock levels at the time of ordering.

Quality, Purity and Regulatory Considerations

Research-grade reagents such as 4-Chloro-1H-pyrazolo[4,3-c]pyridine are intended for laboratory research use only and are not for use in diagnostic procedures, food, drug, or household applications. Quality attributes typically characterized for such building blocks include:

• Purity: Confirmed by HPLC and/or NMR analysis; specific purity values are stated on the certificate of analysis for each batch.
• Identity: Verified by spectroscopic methods such as ¹H NMR, ¹³C NMR, and mass spectrometry.
• Appearance: Typically a solid; color and physical form may vary by batch and should be confirmed via the CoA.

Customers requiring specific purity thresholds or custom analytical packages are encouraged to contact Aladdin Scientific technical support prior to ordering.

Frequently asked questions

What is 4-Chloro-1H-pyrazolo[4,3-c]pyridine used for in research?

4-Chloro-1H-pyrazolo[4,3-c]pyridine is primarily used as a synthetic building block in medicinal chemistry. Its reactive C-4 chloro group undergoes nucleophilic aromatic substitution and cross-coupling reactions, making it valuable for constructing kinase inhibitors, bioactive probe molecules, and diverse heterocyclic compound libraries.

How should 4-Chloro-1H-pyrazolo[4,3-c]pyridine be stored to maintain stability?

The compound should be stored in a tightly sealed container in a cool, dry, and well-ventilated location, away from strong oxidizers and moisture. Please refer to the product Safety Data Sheet (SDS) and Certificate of Analysis (CoA) provided by Aladdin Scientific for batch-specific stability and recommended storage temperature details.

What reactions can be performed at the C-4 chloro position of this compound?

The C-4 chloro group is an electrophilic site that readily participates in nucleophilic aromatic substitution (SNAr) with nitrogen, oxygen, and sulfur nucleophiles such as amines, alcohols, and thiols. It is also compatible with palladium-catalyzed cross-coupling reactions including Suzuki–Miyaura and Buchwald–Hartwig amination, enabling broad structural diversification.

Is 4-Chloro-1H-pyrazolo[4,3-c]pyridine available for bulk or custom orders?

Yes, Aladdin Scientific can accommodate bulk quantity requests and custom purity specifications. Please contact our customer service team with your requirements, referencing SKU C139367, to receive a tailored quotation and discuss lead times.

Can the N-1 position of 4-Chloro-1H-pyrazolo[4,3-c]pyridine be functionalized?

Yes, the N–H at the 1-position of the pyrazole ring is available for N-alkylation and N-acylation under appropriate conditions, providing an additional site for structural modification independent of the C-4 chloro handle. This dual functionalization capability makes the scaffold especially attractive for generating structurally diverse analogues in parallel synthesis.

References

1. Aladdin Scientific product page: 4-Chloro-1H-pyrazolo[4,3-c]pyridine, SKU C139367.
2. General reference: Pyrazolopyridine heterocycles as kinase inhibitor scaffolds — textbook-level medicinal chemistry knowledge; specific literature citations not confirmed from source material.
3. General reference: Nucleophilic aromatic substitution and cross-coupling reactions of chloroheterocycles — standard organic chemistry methodology; no specific citation confirmed from source material.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.